The Zeo sleep monitor from the company Zeo, Inc. monitors sleep quality over time while a person is sleeping. After the person has woken up, the monitored sleep quality is shown on a display to the person. Since only the sleep quality is shown to the person, the person does not know why his sleep had the displayed quality. In particular, the person does not know which actions have to be taken, in order to improve his or her sleep quality, and, thus, based on the information provided by the Zeo sleep monitor it is very difficult to improve the sleep quality.